Signal-to-Interference+Noise Ratio (SINR) is an important metric of communication link quality. SINR estimation is of particular importance for wireless data systems where resources are shared dynamically amongst users. Some applications of SINR estimates are: a) Power Control in CDMA (Code Division Multiple Access) Systems: the receiver estimates the SINR, compares it to a target and commands the transmitter to increase/decrease its transmitted power; and b) Rate Adaptation: the information bit-rate assigned to a user can be dynamically varied based on its link quality and the system load. While such adaptation has limited use in voice systems, it is extremely useful for wireless data systems. Consequently, inaccurate SINR estimates can severely degrade performance and resource utilization.
Typically, the received signal corresponding to the jth demodulated transmitted pilot symbol in a kth timeslot is defined asYkj=akjμk+Ekj  (1)
j=1, 2, . . . , NP 
where μk represents the received signal amplitude (product of transmitted amplitude and channel gain), Ekj is a random variable that represents the noise+interference, akj represents the demodulated pilot symbol-value, and Np is the number of pilot symbols received during the timeslot. Pilot symbol values can be +1 or −1 (in BPSK—Binary Phase Shift Keying), while it is assumed (without any loss of generality) that demodulated pilot symbol values are always +1. It is also assumed that the distribution that characterizes the noise+interference is Gaussian with zero mean and variance σ2. The SINR in the kth timeslot is then defined as:
                              θ          k                =                              μ            K            2                                σ            2                                              (        2        )            and is the parameter to be estimated.
US 2003/0016740 to Jeske et al. proposes a SINR estimator that improves the SINR estimation accuracy. More precisely, Jeske et al. propose a SINR estimator that smoothes the variance σK of the pilot symbol amplitude received during a kth timeslot to obtain an estimated variance {circumflex over (σ)}k with a reduced bias. The use of the estimated variance {circumflex over (σ)}k for the computation of SINR instead of variance σK increases the SINR accuracy. However, Jeske's estimator can still be improved to further increase the accuracy of the estimated SINR.